Chapter 6 - Section 6.2 - Factoring Trinomials of the Form x2+bx+c - Vocabulary and Readiness Check - Page 428: 10

$x^{2}$ + 10x + 24 = (x + 6)(x + 4) Answer = +4.

$x^{2}$ + 10x + 24 = (x + 6)(x + 4) We need two factors of 24 whose sum is 10. But, one factor is already given, 6. Thus other factor is $\frac{24}{6}$ = 4. Since 6 + 4 =10, and 6(4) = 24, the required factor is 4.